diff mbox series

[60/79] commit: Fix completion with extra reference

Message ID 1503965694-10794-61-git-send-email-mdroth@linux.vnet.ibm.com
State New
Headers show
Series Patch Round-up for stable 2.9.1, freeze on 2017-09-04 | expand

Commit Message

Michael Roth Aug. 29, 2017, 12:14 a.m. UTC 
From: Kevin Wolf <kwolf@redhat.com>

commit_complete() can't assume that after its block_job_completed() the
job is actually immediately freed; someone else may still be holding
references. In this case, the op blockers on the intermediate nodes make
the graph reconfiguration in the completion code fail.

Call block_job_remove_all_bdrv() manually so that we know for sure that
any blockers on intermediate nodes are given up.

Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
(cherry picked from commit 4f78a16fee462471416dc49b409d57b2071cf3d9)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
 block/commit.c | 7 +++++++
 1 file changed, 7 insertions(+)
diff mbox series

Patch

diff --git a/block/commit.c b/block/commit.c
index 3bae46e..fba25e2 100644
--- a/block/commit.c
+++ b/block/commit.c
@@ -119,6 +119,13 @@  static void commit_complete(BlockJob *job, void *opaque)
     }
     g_free(s->backing_file_str);
     blk_unref(s->top);
+
+    /* If there is more than one reference to the job (e.g. if called from
+     * block_job_finish_sync()), block_job_completed() won't free it and
+     * therefore the blockers on the intermediate nodes remain. This would
+     * cause bdrv_set_backing_hd() to fail. */
+    block_job_remove_all_bdrv(job);
+
     block_job_completed(&s->common, ret);
     g_free(data);